Expansion joint for roofing and the like surfaces



. Nov. 21, 1939. K. c. JORGENSEN 2,180,904

EXPANSION JOINT FOR ROOFING AND TI IE LIKE SURFACES Filed Dec. 21, 1938\NVE/NTOR K.G.JoReENsN AYTTYS.

Patented Nov. 21, 1939 UNITED STATES EXPANSION JOINT FOR ROOFING AND THEv LIKE SURFACES Knud Christian Jorgensen, Auckland, Auckland, NewZealand Application December 21, I938, Serial No. 247,082 1 In NewZealand July 25, 1938 6 Claims.

This invention relates to an improved expansion joint for roofing andother fiat areas where it is desired to make such roof, or the like,waterproof and weatherproof. In the construction of concrete and brickstructures having flat roofs, it is usual to superimpose on the ordinaryconcrete, or the like mixture forming the roof, a waterproofing layer ofasphalt, or the like. Due to the extremes in temperature, such areas aresubject to considerable contraction and expansion in this top asphaltlayer, and after a period of use, such layer tends to either crack orbuckle. If the former fault develops, then the roof will leak, while ifthe latter fault develops, then the fiat contour of the roof is spoilt.

The present invention is designed with the purpose of constructing anexpansion joint for insertion in such flat roof surfaces at any desiredintervals, which jointing will enable the asphalt layer thereof tocontract or expand independently of the material on which it is laidwithout in any way afiecting the Waterproof properties of such layer andwithout any buckling thereof. This expansion joint is so formed that itwill not allow Water to enter past a joint and seep into the concrete orother material below it. In addition, the joint will also lie flush withthe top surface of the asphalt so that there will be no interference inthe fiat nature of the roof. I'he joint will also be reasonablyfoolproof and require little or no attention after it has beenincorporated in the roof.

In fully describing the invention, reference will be made to theaccompanying drawing, in which:

Figure 1 illustrates a sectional view of the joint in position on theroof.

Figure 2 illustrates a plan thereof, but in the bottom half of thefigure the joint is shown without the associated asphalt covering or theroofing materials below such joint.

Figure 3 shows in diagrammatic form various modifications of the jointwhich will be hereinafter explained.

In the drawing, X is the top portion of the concrete or the like roofupon which an asphalt or the like waterproofing layer Y is to be laid,extending over the whole area of the roof and interposed between suchlayers X and Y are separators Z comprising one or more sheets of fabricsuch as Malthoid or the like waterproofed material.

At regular intervals across the Width and length of the roof surface, anumber of expansion joints are interposed in the material Y so that thelayer may expand and contract, sliding on the separator sheet below it.The expansion joint, ac-

cording to this invention, comprises three sections of shaped metalwhich may advantageously be bent or stamped out of flatsheet metal. Thebase sheet I!) is made with two upwardly extending projectors or tonguesI I and I la towards the centre line of that sheet In and extending forits length. Resting on top of this length ID are two lengths l2 and [2a,the inner end of each of which is bent up to extend forwardly and thendown to form an inverted U shaped channel member Iii-I311, hereinafterto be referred to as channels, which also extend for the length of thesection. These channels enclose respectively the tongues II and Ha, butleave a clear space between them and the sides and top of such tonguesII and Ila.

In use, fabric or the like separators Z are laid on top of the concreteor the like section X, the plate [0 is then laid down on the separatorat the desired position of the expansion joint. The channels l3 andi311. of the lengths l2 andl2a are then filled with grease which shouldbe of such a quality that it will not melt, even at a temperature wellabove the highest normal tem perature the roof would be subject to.

The length I2 is with the contained grease then placed over one side ofthe length I0, so that its channel 13 envelops the tongue H, and thusthere is a grease seal around the sides and top of such tongue.Similarly, the plate I201, is laid over the other portion of the lengthIt, so that its channel section l3a envelops the tongue Ila. To clearlyillustrate this assembly, a plan of the plate I9 is shown in theright-hand bottom quarter of Figure 2, while a plan of the plate l2 inits position on that plate I0 is shown in the left-hand bottom quarterof that Figure 2.

These plates," and In are so constructed and adjusted in relation to thetongues II and II a, which are themselves such a distance apart, thatwhen the tongues are enveloped centrally in the inverted U channels l3and l3a respectively, leaving a clear space all around these respectivetongues, there is also a clear space or gap [4 between the adjacentsides of the sections [2 and 2a. In order that the relative positions ofthese portions l2 and 12a. may be maintained while the asphalt is beinglaid, the space I4 is temporarily filled, as for instance, with a filletof wood. Asphalt or other waterproof material is now laid down. on theroof, preferably to a depth corresponding to the height of the sectionsl2 and Ha,

so that the top of such sections are level and form one, with thefinished roof level. The fillets tending up above-the level of the roof.

are then removed from the gap l4, and the roof is in its finishedcondition. The number of expansion joints in each roof area will dependupon the extremes in temperature such roof is liable to be subject to.

When the heat of the sun causes the sections to expand they may do sowithout cracking or buckling, for the sections 12 and l2a will move intowards each other, reducing the width of the gap I l. Similarly, whenthe roof contracts, the gap M will be widened. The grease in theinverted channels H and Ila will form a waterproof seal, so that nowater can leak from the gap l4 between the plates ID and ll, or ID andHa, and into the space between the layers X and Y. As the joint moves,the area of the space filled with grease on either side of one of thetongues will vary, but there will be no resistance to the movement ofthat joint by the compression of the grease to any one particular sideof the tongue as when the space right of the tongue is reduced in area,a corresponding portion of the grease therein will be transferred overthe top of the tongue into the'correspondingly enlarged space to theleft of the tongue, and vice versa.

To assist in keeping the asphalt to the top faces of the plates l2 and12a, corrugations such as l5 may be formed therein, which corrugations,if desired, may also be filled on their undersides with grease to formfurther waterproof seals between the moveable plates and the fixedplate. Other forms of keying may be used equally effectively, and inaddition the contact surfaces between the moveable plates and the fixedone may be coated with a non-drying tacky, bitumen, or bituminousemulsion. The tongue projections II and Ila are preferably made double,as illustrated in Figure 1 which gives the plate In freedom to expand orcontract sliightly conversely without affecting the efiiciency of thejoint. In-addition, when laying several lengths of this jointing end toend, the fixed lengths are preferably welded end to end, but the ends ofthe moveable lengths overlap each other with a short distance whichenables the moveable lengths to expand and contract longitudinallywithout opening up a gap between their ends.

If high quality grease is used, the seals should last indefinitely, butif desired, covered openings, as for instance as shown at IS in Figure3A, may be made at intervals in the length of the jointing, throughwhich openings grease may be forced into the channels to keep them attheir full capacity. In use, the jointing needs to be inspected atregular intervals in order to ensure that no dirt or accumulated dusthas blocked the gap 14, which would'naturally destroy the efficiency ofthe joint. If, however, it is desired to dispense with the necessity forsuch regular inspections, the gap l4 may be filled with a strip ofeasily compressible material, as for instance a strip of sponge rubberwhich is shown at I! in Figure 3B of the drawing.

Other means of preventing the filling of this gap with accumulated wastemay be used, as for instance, as illustrated in Figure 30, where thechannel 13 is continued, being bent up and then outwardly to form acover plate' l8 for such gap I l. If such a cover plate is used, then itis preferable that instead of being formed in one, with one of themoveable sections of the joint, as is illustrated in the drawing, theplate is loose, being connected to the top of the channel of one .of themoveable sections by any approved means that will preferably not form aprojection ex- With such a plate in use, it may be lifted from time totime to inspect and, if necessary, clean the gap M.

A joint of this nature inserted at intervals in the roof surface andlying flush with it, will not interfere with the use of such roof in theplaying of games thereon and will also not be damaged by people walkingon the actual joint. When it is desired to insert an expansion jointclose to the edge of a wall, one of the moveable plates may be dispensedwith, in which case the fixed plate I0 is turned upwardly at one end tojoin the wall surface, as is illustrated diagrammatically in Figure 3Dof the drawing, its upper edge being overlaid by a flashing 20 let intothe wall.

I claim:

1. An expansion joint for asphalt or like surface coverings consistingin the combination with a break line formed in such covering, of a metalsheet arranged beneath the covering to extend across the break and whichsheet is shaped with two vertically disposed ribs arranged to projectupward within the break and in parallel alignment at a spaced distancefrom each other, and a metal sheet for each side of the break arrangedto extend with one edge in beneath the said covering on such side andabove the first mentioned sheet, and shaped along an outer edgeextending into the break to envelop the sides and top of the aforesaidrib adjacent to its sides of the break, to leave a space between themand which space is filled with grease or like commodity.

2. An expansion joint according to claim 1, in which one or moreseparator sheets of waterproof fabric, or the like, is, or are,interposed between the asphalt or like covering and the surface uponwhich it is laid.

3. An expansion joint according to claim 1, in which the two uppersheets of the joint are each so shaped and united with the asphalt orlike covering that the undersurface of the said sheet rests and slideson the lower sheet for the majority of the formers width, the asphalt orthe like covering being keyed to the top face of this portion of suchtop sheet and such upper sheet at its outer or free end being turned upfor the width of the covering, then out therefrom and finally down tothe original level to form an inverted channel section extending alongthe edge of the covering and adapted to contain grease, and separatedfrom the opposing grease channel in the other top member by a gap.

4. An expansion jointaccording to claim 1, in which the two upper sheetsof the joint are each so shaped and united with the asphalt or likecovering that the under surface of the said sheet rests and slides onthe lower sheet for the majority of the formers width, the asphalt orthe like covering being keyed to the top face of this portion of suchtop sheet and such upper sheet at its outer or free end being turned upfor the width of the covering, then out therefrom and finally down tothe original level to form an inverted channel section extending alongthe edge of the covering and adapted to contain grease, and separatedfrom the opposing grease channel in the other top member by a gap, andin which the lower sheet of the joint has two tongue-like membersprojecting up therefrom in parallel longitudinal alignment and each ofwhich tongues is adapted to enter and be enveloped by the invertedgrease-filled channel of one of the upper sheets, in a manner to leave aclear space between its sides and top and the sides and top of thechannel section.

5. An expansion joint according to claim 1, in which the two uppersheets of the joint are each so shaped and united with the asphalt orlike covering that the under surface of the said sheet rests and slideson the lower sheet for the majority of the formers width, the asphalt orthe like covering being keyed to the top face of this portion of suchtop sheet and such upper sheet at its outer or free end being turned upfor the width of the covering, then out therefrom and finally down tothe original level to form an inverted channel section extending alongthe edge of the covering and adapted to contain grease, and separatedfrom the opposing grease channel in the other top member by a gap, andin which the gap between the free ends of the two upper members iscovered over by a fixed or removeable plate.

6. An expansion joint according to claim 1, in

which the two upper sheets of the joint are each so shaped and unitedwith the asphalt or like covering that the under surface of the saidsheet rests and slides on the lower sheet for the majority of theformers width, the asphalt or the like covering beingkeyed to the topface of this portion of such top sheet and such upper sheet at its outeror free end being turned up for the width of the covering, then outtherefrom and finally down to the original level to form an invertedchannel section extending along the edge of the covering and adapted tocontain grease, and separated from the opposing grease channel in theother top member by a gap, and in which the gap between the free ends ofthe two upper members is filled with an easily compressible material.

KN'UD CHRISTIAN JORGENSEN.

